Currently screendump only supports PPM format, which is un-compressed and not
standard. Added a "format" parameter to qemu monitor screendump capabilites
to support PNG image capture using libpng. The param was added in QAPI schema
of screendump present in ui.json along with png_save() function which converts
pixman_image to PNG. HMP command equivalent was also modified to support the
feature.
Example usage:
{ "execute": "screendump", "arguments": { "filename": "/tmp/image",
"format":"png" } }
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/718
Signed-off-by: Kshitij Suri <kshitij.suri@nutanix.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
---
hmp-commands.hx | 11 ++---
monitor/hmp-cmds.c | 12 +++++-
qapi/ui.json | 24 +++++++++--
ui/console.c | 101 +++++++++++++++++++++++++++++++++++++++++++--
4 files changed, 136 insertions(+), 12 deletions(-)
diff --git a/hmp-commands.hx b/hmp-commands.hx
index 8476277aa9..19b7cab595 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -244,11 +244,12 @@ ERST
{
.name = "screendump",
- .args_type = "filename:F,device:s?,head:i?",
- .params = "filename [device [head]]",
- .help = "save screen from head 'head' of display device 'device' "
- "into PPM image 'filename'",
- .cmd = hmp_screendump,
+ .args_type = "filename:F,format:s?,device:s?,head:i?",
+ .params = "filename [format] [device [head]]",
+ .help = "save screen from head 'head' of display device 'device'"
+ "in specified format 'format' as image 'filename'."
+ "Currently only 'png' and 'ppm' formats are supported.",
+ .cmd = hmp_screendump,
.coroutine = true,
},
diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
index 634968498b..2442bfa989 100644
--- a/monitor/hmp-cmds.c
+++ b/monitor/hmp-cmds.c
@@ -1720,9 +1720,19 @@ hmp_screendump(Monitor *mon, const QDict *qdict)
const char *filename = qdict_get_str(qdict, "filename");
const char *id = qdict_get_try_str(qdict, "device");
int64_t head = qdict_get_try_int(qdict, "head", 0);
+ const char *input_format = qdict_get_try_str(qdict, "format");
Error *err = NULL;
+ ImageFormat format;
- qmp_screendump(filename, id != NULL, id, id != NULL, head, &err);
+ format = qapi_enum_parse(&ImageFormat_lookup, input_format,
+ IMAGE_FORMAT_PPM, &err);
+ if (err) {
+ goto end;
+ }
+
+ qmp_screendump(filename, id != NULL, id, id != NULL, head,
+ input_format != NULL, format, &err);
+end:
hmp_handle_error(mon, err);
}
diff --git a/qapi/ui.json b/qapi/ui.json
index 664da9e462..24371fce05 100644
--- a/qapi/ui.json
+++ b/qapi/ui.json
@@ -157,12 +157,27 @@
##
{ 'command': 'expire_password', 'boxed': true, 'data': 'ExpirePasswordOptions' }
+##
+# @ImageFormat:
+#
+# Supported image format types.
+#
+# @png: PNG format
+#
+# @ppm: PPM format
+#
+# Since: 7.1
+#
+##
+{ 'enum': 'ImageFormat',
+ 'data': ['ppm', 'png'] }
+
##
# @screendump:
#
-# Write a PPM of the VGA screen to a file.
+# Capture the contents of a screen and write it to a file.
#
-# @filename: the path of a new PPM file to store the image
+# @filename: the path of a new file to store the image
#
# @device: ID of the display device that should be dumped. If this parameter
# is missing, the primary display will be used. (Since 2.12)
@@ -171,6 +186,8 @@
# parameter is missing, head #0 will be used. Also note that the head
# can only be specified in conjunction with the device ID. (Since 2.12)
#
+# @format: image format for screendump is specified. (default: ppm) (Since 7.1)
+#
# Returns: Nothing on success
#
# Since: 0.14
@@ -183,7 +200,8 @@
#
##
{ 'command': 'screendump',
- 'data': {'filename': 'str', '*device': 'str', '*head': 'int'},
+ 'data': {'filename': 'str', '*device': 'str', '*head': 'int',
+ '*format': 'ImageFormat'},
'coroutine': true }
##
diff --git a/ui/console.c b/ui/console.c
index da434ce1b2..f42f64d556 100644
--- a/ui/console.c
+++ b/ui/console.c
@@ -37,6 +37,9 @@
#include "exec/memory.h"
#include "io/channel-file.h"
#include "qom/object.h"
+#ifdef CONFIG_PNG
+#include <png.h>
+#endif
#define DEFAULT_BACKSCROLL 512
#define CONSOLE_CURSOR_PERIOD 500
@@ -291,6 +294,89 @@ void graphic_hw_invalidate(QemuConsole *con)
}
}
+#ifdef CONFIG_PNG
+/**
+ * png_save: Take a screenshot as PNG
+ *
+ * Saves screendump as a PNG file
+ *
+ * Returns true for success or false for error.
+ *
+ * @fd: File descriptor for PNG file.
+ * @image: Image data in pixman format.
+ * @errp: Pointer to an error.
+ */
+static bool png_save(int fd, pixman_image_t *image, Error **errp)
+{
+ int width = pixman_image_get_width(image);
+ int height = pixman_image_get_height(image);
+ g_autofree png_struct *png_ptr = NULL;
+ g_autofree png_info *info_ptr = NULL;
+ g_autoptr(pixman_image_t) linebuf =
+ qemu_pixman_linebuf_create(PIXMAN_a8r8g8b8, width);
+ uint8_t *buf = (uint8_t *)pixman_image_get_data(linebuf);
+ FILE *f = fdopen(fd, "wb");
+ int y;
+ if (!f) {
+ error_setg_errno(errp, errno,
+ "Failed to create file from file descriptor");
+ return false;
+ }
+
+ png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL,
+ NULL, NULL);
+ if (!png_ptr) {
+ error_setg(errp, "PNG creation failed. Unable to write struct");
+ fclose(f);
+ return false;
+ }
+
+ info_ptr = png_create_info_struct(png_ptr);
+
+ if (!info_ptr) {
+ error_setg(errp, "PNG creation failed. Unable to write info");
+ fclose(f);
+ png_destroy_write_struct(&png_ptr, &info_ptr);
+ return false;
+ }
+
+ png_init_io(png_ptr, f);
+
+ png_set_IHDR(png_ptr, info_ptr, width, height, 8,
+ PNG_COLOR_TYPE_RGB_ALPHA, PNG_INTERLACE_NONE,
+ PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+
+ png_write_info(png_ptr, info_ptr);
+
+ for (y = 0; y < height; ++y) {
+ qemu_pixman_linebuf_fill(linebuf, image, width, 0, y);
+ png_write_row(png_ptr, buf);
+ }
+ qemu_pixman_image_unref(linebuf);
+
+ png_write_end(png_ptr, NULL);
+
+ png_destroy_write_struct(&png_ptr, &info_ptr);
+
+ if (fclose(f) != 0) {
+ error_setg_errno(errp, errno,
+ "PNG creation failed. Unable to close file");
+ return false;
+ }
+
+ return true;
+}
+
+#else /* no png support */
+
+static bool png_save(int fd, pixman_image_t *image, Error **errp)
+{
+ error_setg(errp, "Enable PNG support with libpng for screendump");
+ return false;
+}
+
+#endif /* CONFIG_PNG */
+
static bool ppm_save(int fd, pixman_image_t *image, Error **errp)
{
int width = pixman_image_get_width(image);
@@ -329,7 +415,8 @@ static void graphic_hw_update_bh(void *con)
/* Safety: coroutine-only, concurrent-coroutine safe, main thread only */
void coroutine_fn
qmp_screendump(const char *filename, bool has_device, const char *device,
- bool has_head, int64_t head, Error **errp)
+ bool has_head, int64_t head,
+ bool has_format, ImageFormat format, Error **errp)
{
g_autoptr(pixman_image_t) image = NULL;
QemuConsole *con;
@@ -385,8 +472,16 @@ qmp_screendump(const char *filename, bool has_device, const char *device,
* yields and releases the BQL. It could produce corrupted dump, but
* it should be otherwise safe.
*/
- if (!ppm_save(fd, image, errp)) {
- qemu_unlink(filename);
+ if (has_format && format == IMAGE_FORMAT_PNG) {
+ /* PNG format specified for screendump */
+ if (!png_save(fd, image, errp)) {
+ qemu_unlink(filename);
+ }
+ } else {
+ /* PPM format specified/default for screendump */
+ if (!ppm_save(fd, image, errp)) {
+ qemu_unlink(filename);
+ }
}
}
--
2.22.3
Dave, please have a look at the HMP compatibility issue in
hmp-command.hx below.
Kshitij Suri <kshitij.suri@nutanix.com> writes:
> Currently screendump only supports PPM format, which is un-compressed and not
> standard.
If "standard" means "have to pay a standards organization $$$ to access
the spec", PPM is not standard. If it means "widely supported", it
certainly is. I'd drop "and not standard". Suggestion, not demand.
> Added a "format" parameter to qemu monitor screendump capabilites
> to support PNG image capture using libpng. The param was added in QAPI schema
> of screendump present in ui.json along with png_save() function which converts
> pixman_image to PNG. HMP command equivalent was also modified to support the
> feature.
Suggest to use imperative mood to describe the commit, and omit details
that aren't necessary here:
Add a "format" parameter to QMP and HMP screendump command
to support PNG image capture using libpng.
>
> Example usage:
> { "execute": "screendump", "arguments": { "filename": "/tmp/image",
> "format":"png" } }
Providing an example in the commit message is always nice, thanks!
>
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/718
>
> Signed-off-by: Kshitij Suri <kshitij.suri@nutanix.com>
>
> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
> ---
> hmp-commands.hx | 11 ++---
> monitor/hmp-cmds.c | 12 +++++-
> qapi/ui.json | 24 +++++++++--
> ui/console.c | 101 +++++++++++++++++++++++++++++++++++++++++++--
> 4 files changed, 136 insertions(+), 12 deletions(-)
>
> diff --git a/hmp-commands.hx b/hmp-commands.hx
> index 8476277aa9..19b7cab595 100644
> --- a/hmp-commands.hx
> +++ b/hmp-commands.hx
> @@ -244,11 +244,12 @@ ERST
>
> {
> .name = "screendump",
> - .args_type = "filename:F,device:s?,head:i?",
> - .params = "filename [device [head]]",
> - .help = "save screen from head 'head' of display device 'device' "
> - "into PPM image 'filename'",
> - .cmd = hmp_screendump,
> + .args_type = "filename:F,format:s?,device:s?,head:i?",
Incompatible change: meaning of "screendump ONE TWO" changes from
filename=ONE, device=TWO to filename=ONE, format=TWO.
As HMP is not a stable interface, incompatible change is permissible.
But is this one wise?
Could we add the new argument at the end instead?
.args_type = "filename:F,device:s?,head:i?,format:s?",
Could we do *without* an argument, and derive the format from the
filename extension? .png means format=png, anything else format=ppm.
Would be a bad idea for QMP. Okay for HMP?
> + .params = "filename [format] [device [head]]",
This tells us that parameter format can be omitted like so
screendump foo.ppm device-id
which isn't true. Better: "filename [format [device [head]]".
> + .help = "save screen from head 'head' of display device 'device'"
> + "in specified format 'format' as image 'filename'."
> + "Currently only 'png' and 'ppm' formats are supported.",
> + .cmd = hmp_screendump,
> .coroutine = true,
> },
>
> diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
> index 634968498b..2442bfa989 100644
> --- a/monitor/hmp-cmds.c
> +++ b/monitor/hmp-cmds.c
> @@ -1720,9 +1720,19 @@ hmp_screendump(Monitor *mon, const QDict *qdict)
> const char *filename = qdict_get_str(qdict, "filename");
> const char *id = qdict_get_try_str(qdict, "device");
> int64_t head = qdict_get_try_int(qdict, "head", 0);
> + const char *input_format = qdict_get_try_str(qdict, "format");
> Error *err = NULL;
> + ImageFormat format;
>
> - qmp_screendump(filename, id != NULL, id, id != NULL, head, &err);
> + format = qapi_enum_parse(&ImageFormat_lookup, input_format,
> + IMAGE_FORMAT_PPM, &err);
> + if (err) {
> + goto end;
> + }
> +
> + qmp_screendump(filename, id != NULL, id, id != NULL, head,
> + input_format != NULL, format, &err);
> +end:
> hmp_handle_error(mon, err);
> }
>
> diff --git a/qapi/ui.json b/qapi/ui.json
> index 664da9e462..24371fce05 100644
> --- a/qapi/ui.json
> +++ b/qapi/ui.json
> @@ -157,12 +157,27 @@
> ##
> { 'command': 'expire_password', 'boxed': true, 'data': 'ExpirePasswordOptions' }
>
> +##
> +# @ImageFormat:
> +#
> +# Supported image format types.
> +#
> +# @png: PNG format
> +#
> +# @ppm: PPM format
> +#
> +# Since: 7.1
> +#
> +##
> +{ 'enum': 'ImageFormat',
> + 'data': ['ppm', 'png'] }
> +
> ##
> # @screendump:
> #
> -# Write a PPM of the VGA screen to a file.
> +# Capture the contents of a screen and write it to a file.
> #
> -# @filename: the path of a new PPM file to store the image
> +# @filename: the path of a new file to store the image
> #
> # @device: ID of the display device that should be dumped. If this parameter
> # is missing, the primary display will be used. (Since 2.12)
> @@ -171,6 +186,8 @@
> # parameter is missing, head #0 will be used. Also note that the head
> # can only be specified in conjunction with the device ID. (Since 2.12)
> #
> +# @format: image format for screendump is specified. (default: ppm) (Since 7.1)
Recommend
# @format: image format for screendump (default: ppm) (Since 7.1)
> +#
> # Returns: Nothing on success
> #
> # Since: 0.14
> @@ -183,7 +200,8 @@
> #
> ##
> { 'command': 'screendump',
> - 'data': {'filename': 'str', '*device': 'str', '*head': 'int'},
> + 'data': {'filename': 'str', '*device': 'str', '*head': 'int',
> + '*format': 'ImageFormat'},
> 'coroutine': true }
>
> ##
QAPI schema
Acked-by: Markus Armbruster <armbru@redhat.com>
[...]
* Markus Armbruster (armbru@redhat.com) wrote:
> Dave, please have a look at the HMP compatibility issue in
> hmp-command.hx below.
>
> Kshitij Suri <kshitij.suri@nutanix.com> writes:
>
> > Currently screendump only supports PPM format, which is un-compressed and not
> > standard.
>
> If "standard" means "have to pay a standards organization $$$ to access
> the spec", PPM is not standard. If it means "widely supported", it
> certainly is. I'd drop "and not standard". Suggestion, not demand.
>
> > Added a "format" parameter to qemu monitor screendump capabilites
> > to support PNG image capture using libpng. The param was added in QAPI schema
> > of screendump present in ui.json along with png_save() function which converts
> > pixman_image to PNG. HMP command equivalent was also modified to support the
> > feature.
>
> Suggest to use imperative mood to describe the commit, and omit details
> that aren't necessary here:
>
> Add a "format" parameter to QMP and HMP screendump command
> to support PNG image capture using libpng.
>
> >
> > Example usage:
> > { "execute": "screendump", "arguments": { "filename": "/tmp/image",
> > "format":"png" } }
>
> Providing an example in the commit message is always nice, thanks!
>
> >
> > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/718
> >
> > Signed-off-by: Kshitij Suri <kshitij.suri@nutanix.com>
> >
> > Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
> > ---
> > hmp-commands.hx | 11 ++---
> > monitor/hmp-cmds.c | 12 +++++-
> > qapi/ui.json | 24 +++++++++--
> > ui/console.c | 101 +++++++++++++++++++++++++++++++++++++++++++--
> > 4 files changed, 136 insertions(+), 12 deletions(-)
> >
> > diff --git a/hmp-commands.hx b/hmp-commands.hx
> > index 8476277aa9..19b7cab595 100644
> > --- a/hmp-commands.hx
> > +++ b/hmp-commands.hx
> > @@ -244,11 +244,12 @@ ERST
> >
> > {
> > .name = "screendump",
> > - .args_type = "filename:F,device:s?,head:i?",
> > - .params = "filename [device [head]]",
> > - .help = "save screen from head 'head' of display device 'device' "
> > - "into PPM image 'filename'",
> > - .cmd = hmp_screendump,
> > + .args_type = "filename:F,format:s?,device:s?,head:i?",
>
> Incompatible change: meaning of "screendump ONE TWO" changes from
> filename=ONE, device=TWO to filename=ONE, format=TWO.
>
> As HMP is not a stable interface, incompatible change is permissible.
> But is this one wise?
>
> Could we add the new argument at the end instead?
>
> .args_type = "filename:F,device:s?,head:i?,format:s?",
>
> Could we do *without* an argument, and derive the format from the
> filename extension? .png means format=png, anything else format=ppm.
> Would be a bad idea for QMP. Okay for HMP?
Could we use the new optional flag with value that Stefan Reiter
added in 26fcd76 ? (and used in 675fd3c)
In which case I think we'd have:
"filename:F,format:-fs,device:s?,head:i?"
That would seem cleanest; Extracting from the filename would be OKish
if it errored if the format wasn't obvious.
Dave
> > + .params = "filename [format] [device [head]]",
>
> This tells us that parameter format can be omitted like so
>
> screendump foo.ppm device-id
>
> which isn't true. Better: "filename [format [device [head]]".
>
> > + .help = "save screen from head 'head' of display device 'device'"
> > + "in specified format 'format' as image 'filename'."
> > + "Currently only 'png' and 'ppm' formats are supported.",
> > + .cmd = hmp_screendump,
> > .coroutine = true,
> > },
> >
> > diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
> > index 634968498b..2442bfa989 100644
> > --- a/monitor/hmp-cmds.c
> > +++ b/monitor/hmp-cmds.c
> > @@ -1720,9 +1720,19 @@ hmp_screendump(Monitor *mon, const QDict *qdict)
> > const char *filename = qdict_get_str(qdict, "filename");
> > const char *id = qdict_get_try_str(qdict, "device");
> > int64_t head = qdict_get_try_int(qdict, "head", 0);
> > + const char *input_format = qdict_get_try_str(qdict, "format");
> > Error *err = NULL;
> > + ImageFormat format;
> >
> > - qmp_screendump(filename, id != NULL, id, id != NULL, head, &err);
> > + format = qapi_enum_parse(&ImageFormat_lookup, input_format,
> > + IMAGE_FORMAT_PPM, &err);
> > + if (err) {
> > + goto end;
> > + }
> > +
> > + qmp_screendump(filename, id != NULL, id, id != NULL, head,
> > + input_format != NULL, format, &err);
> > +end:
> > hmp_handle_error(mon, err);
> > }
> >
> > diff --git a/qapi/ui.json b/qapi/ui.json
> > index 664da9e462..24371fce05 100644
> > --- a/qapi/ui.json
> > +++ b/qapi/ui.json
> > @@ -157,12 +157,27 @@
> > ##
> > { 'command': 'expire_password', 'boxed': true, 'data': 'ExpirePasswordOptions' }
> >
> > +##
> > +# @ImageFormat:
> > +#
> > +# Supported image format types.
> > +#
> > +# @png: PNG format
> > +#
> > +# @ppm: PPM format
> > +#
> > +# Since: 7.1
> > +#
> > +##
> > +{ 'enum': 'ImageFormat',
> > + 'data': ['ppm', 'png'] }
> > +
> > ##
> > # @screendump:
> > #
> > -# Write a PPM of the VGA screen to a file.
> > +# Capture the contents of a screen and write it to a file.
> > #
> > -# @filename: the path of a new PPM file to store the image
> > +# @filename: the path of a new file to store the image
> > #
> > # @device: ID of the display device that should be dumped. If this parameter
> > # is missing, the primary display will be used. (Since 2.12)
> > @@ -171,6 +186,8 @@
> > # parameter is missing, head #0 will be used. Also note that the head
> > # can only be specified in conjunction with the device ID. (Since 2.12)
> > #
> > +# @format: image format for screendump is specified. (default: ppm) (Since 7.1)
>
> Recommend
>
> # @format: image format for screendump (default: ppm) (Since 7.1)
>
> > +#
> > # Returns: Nothing on success
> > #
> > # Since: 0.14
> > @@ -183,7 +200,8 @@
> > #
> > ##
> > { 'command': 'screendump',
> > - 'data': {'filename': 'str', '*device': 'str', '*head': 'int'},
> > + 'data': {'filename': 'str', '*device': 'str', '*head': 'int',
> > + '*format': 'ImageFormat'},
> > 'coroutine': true }
> >
> > ##
>
> QAPI schema
> Acked-by: Markus Armbruster <armbru@redhat.com>
>
> [...]
>
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
On 01/04/22 4:50 pm, Markus Armbruster wrote:
> Dave, please have a look at the HMP compatibility issue in
> hmp-command.hx below.
>
> Kshitij Suri <kshitij.suri@nutanix.com> writes:
>
>> Currently screendump only supports PPM format, which is un-compressed and not
>> standard.
> If "standard" means "have to pay a standards organization $$$ to access
> the spec", PPM is not standard. If it means "widely supported", it
> certainly is. I'd drop "and not standard". Suggestion, not demand.
Makes sense. Will modify it in the updated patch.
>
>> Added a "format" parameter to qemu monitor screendump capabilites
>> to support PNG image capture using libpng. The param was added in QAPI schema
>> of screendump present in ui.json along with png_save() function which converts
>> pixman_image to PNG. HMP command equivalent was also modified to support the
>> feature.
> Suggest to use imperative mood to describe the commit, and omit details
> that aren't necessary here:
>
> Add a "format" parameter to QMP and HMP screendump command
> to support PNG image capture using libpng.
Yes, will reduce the verbosity of the commit message.
>> Example usage:
>> { "execute": "screendump", "arguments": { "filename": "/tmp/image",
>> "format":"png" } }
> Providing an example in the commit message is always nice, thanks!
Thank you!
>
>> Resolves: https://urldefense.proofpoint.com/v2/url?u=https-3A__gitlab.com_qemu-2Dproject_qemu_-2D_issues_718&d=DwIFaQ&c=s883GpUCOChKOHiocYtGcg&r=utjv19Ej9Fb0TB7_DX0o3faQ-OAm2ypPniPyqVSoj_w&m=oODILSxODcEhktuPJ-SfVt-MW867cpF_TvDe-WJyNRXx84FinSifhtp6-Racosb0&s=89nTa5MLAr16WtPfrm4aYkwWlPuRs6yuaD22dZTE_pM&e=
>>
>> Signed-off-by: Kshitij Suri <kshitij.suri@nutanix.com>
>>
>> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
>> ---
>> hmp-commands.hx | 11 ++---
>> monitor/hmp-cmds.c | 12 +++++-
>> qapi/ui.json | 24 +++++++++--
>> ui/console.c | 101 +++++++++++++++++++++++++++++++++++++++++++--
>> 4 files changed, 136 insertions(+), 12 deletions(-)
>>
>> diff --git a/hmp-commands.hx b/hmp-commands.hx
>> index 8476277aa9..19b7cab595 100644
>> --- a/hmp-commands.hx
>> +++ b/hmp-commands.hx
>> @@ -244,11 +244,12 @@ ERST
>>
>> {
>> .name = "screendump",
>> - .args_type = "filename:F,device:s?,head:i?",
>> - .params = "filename [device [head]]",
>> - .help = "save screen from head 'head' of display device 'device' "
>> - "into PPM image 'filename'",
>> - .cmd = hmp_screendump,
>> + .args_type = "filename:F,format:s?,device:s?,head:i?",
> Incompatible change: meaning of "screendump ONE TWO" changes from
> filename=ONE, device=TWO to filename=ONE, format=TWO.
>
> As HMP is not a stable interface, incompatible change is permissible.
> But is this one wise?
>
> Could we add the new argument at the end instead?
>
> .args_type = "filename:F,device:s?,head:i?,format:s?",
>
> Could we do *without* an argument, and derive the format from the
> filename extension? .png means format=png, anything else format=ppm.
> Would be a bad idea for QMP. Okay for HMP?
Should I go ahead with extracting format from filename provided for HMP?
>
>> + .params = "filename [format] [device [head]]",
> This tells us that parameter format can be omitted like so
>
> screendump foo.ppm device-id
>
> which isn't true. Better: "filename [format [device [head]]".
Thank you will modify it!
>
>> + .help = "save screen from head 'head' of display device 'device'"
>> + "in specified format 'format' as image 'filename'."
>> + "Currently only 'png' and 'ppm' formats are supported.",
>> + .cmd = hmp_screendump,
>> .coroutine = true,
>> },
>>
>> diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
>> index 634968498b..2442bfa989 100644
>> --- a/monitor/hmp-cmds.c
>> +++ b/monitor/hmp-cmds.c
>> @@ -1720,9 +1720,19 @@ hmp_screendump(Monitor *mon, const QDict *qdict)
>> const char *filename = qdict_get_str(qdict, "filename");
>> const char *id = qdict_get_try_str(qdict, "device");
>> int64_t head = qdict_get_try_int(qdict, "head", 0);
>> + const char *input_format = qdict_get_try_str(qdict, "format");
>> Error *err = NULL;
>> + ImageFormat format;
>>
>> - qmp_screendump(filename, id != NULL, id, id != NULL, head, &err);
>> + format = qapi_enum_parse(&ImageFormat_lookup, input_format,
>> + IMAGE_FORMAT_PPM, &err);
>> + if (err) {
>> + goto end;
>> + }
>> +
>> + qmp_screendump(filename, id != NULL, id, id != NULL, head,
>> + input_format != NULL, format, &err);
>> +end:
>> hmp_handle_error(mon, err);
>> }
>>
>> diff --git a/qapi/ui.json b/qapi/ui.json
>> index 664da9e462..24371fce05 100644
>> --- a/qapi/ui.json
>> +++ b/qapi/ui.json
>> @@ -157,12 +157,27 @@
>> ##
>> { 'command': 'expire_password', 'boxed': true, 'data': 'ExpirePasswordOptions' }
>>
>> +##
>> +# @ImageFormat:
>> +#
>> +# Supported image format types.
>> +#
>> +# @png: PNG format
>> +#
>> +# @ppm: PPM format
>> +#
>> +# Since: 7.1
>> +#
>> +##
>> +{ 'enum': 'ImageFormat',
>> + 'data': ['ppm', 'png'] }
>> +
>> ##
>> # @screendump:
>> #
>> -# Write a PPM of the VGA screen to a file.
>> +# Capture the contents of a screen and write it to a file.
>> #
>> -# @filename: the path of a new PPM file to store the image
>> +# @filename: the path of a new file to store the image
>> #
>> # @device: ID of the display device that should be dumped. If this parameter
>> # is missing, the primary display will be used. (Since 2.12)
>> @@ -171,6 +186,8 @@
>> # parameter is missing, head #0 will be used. Also note that the head
>> # can only be specified in conjunction with the device ID. (Since 2.12)
>> #
>> +# @format: image format for screendump is specified. (default: ppm) (Since 7.1)
> Recommend
>
> # @format: image format for screendump (default: ppm) (Since 7.1)
Will change it in the updated patch
>
>> +#
>> # Returns: Nothing on success
>> #
>> # Since: 0.14
>> @@ -183,7 +200,8 @@
>> #
>> ##
>> { 'command': 'screendump',
>> - 'data': {'filename': 'str', '*device': 'str', '*head': 'int'},
>> + 'data': {'filename': 'str', '*device': 'str', '*head': 'int',
>> + '*format': 'ImageFormat'},
>> 'coroutine': true }
>>
>> ##
Thank you for your review!
Regards,
Kshitij Suri
> QAPI schema
> Acked-by: Markus Armbruster <armbru@redhat.com>
>
> [...]
>
Kshitij Suri <kshitij.suri@nutanix.com> writes:
> On 01/04/22 4:50 pm, Markus Armbruster wrote:
>> Dave, please have a look at the HMP compatibility issue in
>> hmp-command.hx below.
>>
>> Kshitij Suri <kshitij.suri@nutanix.com> writes:
>>
>>> Currently screendump only supports PPM format, which is un-compressed and not
>>> standard.
>> If "standard" means "have to pay a standards organization $$$ to access
>> the spec", PPM is not standard. If it means "widely supported", it
>> certainly is. I'd drop "and not standard". Suggestion, not demand.
>
> Makes sense. Will modify it in the updated patch.
>
>>> Added a "format" parameter to qemu monitor screendump capabilites
>>> to support PNG image capture using libpng. The param was added in QAPI schema
>>> of screendump present in ui.json along with png_save() function which converts
>>> pixman_image to PNG. HMP command equivalent was also modified to support the
>>> feature.
>> Suggest to use imperative mood to describe the commit, and omit details
>> that aren't necessary here:
>>
>> Add a "format" parameter to QMP and HMP screendump command
>> to support PNG image capture using libpng.
>
> Yes, will reduce the verbosity of the commit message.
>
>>> Example usage:
>>> { "execute": "screendump", "arguments": { "filename": "/tmp/image",
>>> "format":"png" } }
>>
>> Providing an example in the commit message is always nice, thanks!
>
> Thank you!
>
>>> Resolves: https://urldefense.proofpoint.com/v2/url?u=https-3A__gitlab.com_qemu-2Dproject_qemu_-2D_issues_718&d=DwIFaQ&c=s883GpUCOChKOHiocYtGcg&r=utjv19Ej9Fb0TB7_DX0o3faQ-OAm2ypPniPyqVSoj_w&m=oODILSxODcEhktuPJ-SfVt-MW867cpF_TvDe-WJyNRXx84FinSifhtp6-Racosb0&s=89nTa5MLAr16WtPfrm4aYkwWlPuRs6yuaD22dZTE_pM&e=
>>>
>>> Signed-off-by: Kshitij Suri <kshitij.suri@nutanix.com>
>>>
>>> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
>>> ---
>>> hmp-commands.hx | 11 ++---
>>> monitor/hmp-cmds.c | 12 +++++-
>>> qapi/ui.json | 24 +++++++++--
>>> ui/console.c | 101 +++++++++++++++++++++++++++++++++++++++++++--
>>> 4 files changed, 136 insertions(+), 12 deletions(-)
>>>
>>> diff --git a/hmp-commands.hx b/hmp-commands.hx
>>> index 8476277aa9..19b7cab595 100644
>>> --- a/hmp-commands.hx
>>> +++ b/hmp-commands.hx
>>> @@ -244,11 +244,12 @@ ERST
>>> {
>>> .name = "screendump",
>>> - .args_type = "filename:F,device:s?,head:i?",
>>> - .params = "filename [device [head]]",
>>> - .help = "save screen from head 'head' of display device 'device' "
>>> - "into PPM image 'filename'",
>>> - .cmd = hmp_screendump,
>>> + .args_type = "filename:F,format:s?,device:s?,head:i?",
>>
>> Incompatible change: meaning of "screendump ONE TWO" changes from
>> filename=ONE, device=TWO to filename=ONE, format=TWO.
>>
>> As HMP is not a stable interface, incompatible change is permissible.
>> But is this one wise?
>>
>> Could we add the new argument at the end instead?
>>
>> .args_type = "filename:F,device:s?,head:i?,format:s?",
>>
>> Could we do *without* an argument, and derive the format from the
>> filename extension? .png means format=png, anything else format=ppm.
>> Would be a bad idea for QMP. Okay for HMP?
>
> Should I go ahead with extracting format from filename provided for HMP?
Let's give Dave a chance to chime in.
[...]
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